The present invention is utilized with a carousel printing machine comprising a plurality of print stations with stationary screen frames spaced circumferentially about the machine, and arms with work support pallets thereon rotatable into positions under successive stationary screen frames for printing a plurality of registering images on a workpiece on each work support pallet. Such machines are shown and described in U.S. Pat. No. 5,226,362 to Iaccino, et al., and in U.S. Pat. No. 5,806,422 to Alan Hamu.
A work support pallet must register with respective screen frames at successive screen print stations. It has conventionally been required that work support pallets be removed and later re-mounted on machine arms in the process of alignment of work support pallets with screen frames. That is, a support pallet is removed, replaced with an alignment pallet or pallet tool, and then re-mounted and secured on the machine arm after registration with a screen frame. Time, labor, and expense are involved in such procedures.
The present invention provides the advantages of a pallet tool being pre-registered relative to a machine arm, and the pallet tool being essentially permanently on the arm, thereby simplifying or eliminating the necessity for alignment of work support pallets with machine arms and screen frames in successive operations. The removal of a support pallet from the arm and later re-assembly for registration are eliminated.
According to the invention, a pallet tool is supported relative to a machine arm by pairs of pivot arms pivotally mounted in spaced relation on the pallet tool and on the arm, thus to provide accurate movement of the pallet tool relative to the arm into proximity with a screen frame. The pallet tool is a relatively rigid structure to provide accuracy of its alignment relative to a machine arm and a work support pallet. With the work support pallet already accurately registered relative to the machine arm, independently of the pallet tool, the pallet tool is shuttled or swung into position in underlying relation with the work support pallet, the pallet tool maintaining alignment relative to the arm. Registration means, such as inter-engaging registration pins and openings are utilized to register the pallet tool with the screen frame.